The Huntington Education Department
Mini-Ecosystems:
Venus Flytrap Terrariums as a Study of Plant
Adaptations
Grades 4 - 8
INTRODUCTION
In preparation for a school visit to the Huntington Botanical
Gardens' Reading Plants tour, we will investigate the interesting
adaptations of Venus Flytraps through the creation of a small
classroom terrarium.
OBJECTIVE
To encourage the exploration of plant structure in order to
learn about adaptation in different climates and environments.
BACKGROUND: Plant Adaptations and Venus Flytraps
During your visit to the Huntington Botanical Gardens, your
class will visit three different gardens: the Desert Garden,
Lily Pond Garden, and the Jungle Garden. Each of these gardens
represents a distinct ecosystem, where plants are adapted to
the unique conditions of their local environment, from the arid
and sunny climate of the Desert Garden, to the wet and shady
Jungle Garden. We can learn a lot about a plant's survival in
its environment by examining its shape, size, and structure.
Depending on the light and water available in their environment,
plants have developed special adaptations over many generations.
The spines on cactus are modified leaves, so that while they
can harness the sun's energy in photosynthesis, their small shape
helps prevent water loss in dry, desert climates. Meanwhile,
in a rain forest environment, plants often have extremely large
leaves to maximize the sunlight they can capture from the shady
forest floor.
Venus Flytraps are particularly revealing plants, as they
are uniquely adapted to their nutrient-poor bog environment.
In their native environment, Venus Flytraps don't receive the
nutrients (primarily nitrogen) they need from the soil. Therefore,
they have evolved their fascinating leaf structure to catch flies
and other small insects to digest in order to gain these important
nutrients.
While we will be putting together a Venus Flytrap Terrarium,
you may use different plants in your classroom to create terrarium
with your students. You may want to create different environments
in preparation for your visit to the Huntington. We recommend
creating both desert and jungle terrariums in order to study
the adaptations of plants in these distinct environments. Plants
that are easy to find at a local nursery for the desert terrarium
are: Jade, Aloe, Crassula, and small cacti. For the tropical
terrarium, try Philodendron, Dieffenbachia, Croton, ferns, and
begonias.
MATERIALS NEEDED
- 2-Liter clear plastic bottle
- scissors
- potting soil (peat and sand mixture)
- Venus Flytrap plant
- additional bog plants: baby's tears, pink polka-dot plant
- distilled water
PROCEDURE
Guide your students through a discussion of plants —
what all plants need (sunlight, nutrients, water), and different
adaptations that allow them to grow and reproduce.
It is best to cut the plastic bottles in half ahead of time
(in the horizontal direction). Cut slits in the top half so that
it will fit around the bottom half. Discard the bottle cap. When
you show the bottles to the students, discuss how the clear plastic
bottle will allow light in to the terrarium and why this is important
for the survival of the plants. It is also a good idea to talk
about the water cycle — how water is given off by the plants
(transpiration), and how some of the water will cycle within
the terrarium, condensing visibly on the surface of the bottle,
and maintaining a more humid environment for the plants.
- Take the time to examine the soil you will use. Explore how
it feels, what it is made of (the best soil for Venus Flytraps
is a peat and sand mixture), how moist or dry it is.
- Fill the bottom half of the bottle ½ - 2/3 full with
soil.
- Examine and discuss the plants you will be putting in the
terrarium.
- Arrange and plant the chosen plants. When transplanting,
gently remove the plants from their old containers, taking care
not to damage their roots. Dig a small hole where you will plant
them, then place the roots in the ground and cover them with
soil. Don't forget that plants grow and they will need a little
space!
- Water your terrarium, the soil should be kept slightly moist.
Note: Venus Flytraps must have distilled water!
The chlorine in tap water will kill them.
- Find a sunny spot for your terrarium. It is best if it can
be in filtered sunlight. Windowsills are great!
- Check your terrarium periodically, observe the changes you
see in the plants and watch for signs of the water cycle!
Extra Tips on Venus Flytrap Care:
Don't feed your Venus Flytrap. The Flytraps are skillful in
trapping their own food, and extra feeding is not necessary.
Avoid playing with the leaves because each leaf can only close
3-4 times before it dies. The leaves are important to the plant's
survival.
As your plant gets older, some of the leaves will die and
turn black, just like any other plant. These leaves should be
cut off with scissors — just cut the leaf, not the whole
stalk.
DISCUSSION QUESTIONS
- What do plants need to survive?
- What is an environment? An ecosystem?
- What are adaptations?
- How can we learn about a plant's environment just by looking
at the plant?
When examining a plant:
- How would you describe this plant?
- What do you notice about its leaves? Stems? Flowers?
- What kind of an environment do you think this plant lives
in?
- How do you know?
- Does this plant need a lot of water?
EXTENSION QUESTIONS
- What kind of environment do we live in?
- What kinds of plants can you find in your neighborhood that
are native to Southern California?
- How are these plants similar and different to the plants
at the Huntington?
- How would you compare the different plants in your neighborhood?
- Why are plants important to people?
- How do you use plants everyday?
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